Seasonal affective disorder, commonly called SAD, is nothing new. This "winter depression" can affect up to 10 percent of the population and includes symptoms like anxiety, loss of energy, social withdrawal and suicidal thoughts.

SAD was first recognized by the National Institute of Mental Health in 1984 and has been successfully treated with light therapy, psychological counseling or, in more severe cases, medication.

New, however, is a series of recent studies indicating that simply being out in nature can provide significant physical and mental health benefits. Unfortunately, many of us are not getting enough nature.

So what does "nature deficit" have to do with seniors? As seniors age, access to and interest in being outside can wane. For seniors who are not ambulatory, caregivers must make a special effort to get them outside.

For older seniors in particular, nature deficit can be extremely detrimental for both mental and physical health. Research shows a link between reduced exposure to nature and a higher risk for obesity, cancer, heart disease, anxiety and depression.

The effects of nature deficit are not only physical, according to Dr. David Strayer, a neuroscientist at the University of Utah. Strayer's research shows that modern living can overtax the brain areas that are involved in thinking creatively and developing a sense of identity.

"Getting out into nature allows those parts of your brain to restore and replenish themselves," Strayer says. People are more creative and less stressed after spending time in nature.

In Japan, scientists are measuring the physical effects of "forest bathing," where test subjects sit in or walk through forests or wooded areas. The results show that the subjects had increased immune function almost immediately, and men who took two-hour walks through a forested area for two days showed a lasting spike in white blood cells — the cells that combat illness in our bodies.

Additionally, the test subjects' blood pressure, resting heart rate and cortisol levels — a stress hormone — were all significantly lower after nature bathing. Researchers believe part of the "nature benefit" comes from phytoncides, an airborne chemical that is emitted from plants and which also seems to benefit humans.

The findings of these studies are so compelling that some doctors are writing "nature prescriptions" — telling patients to commune with nature to help prevent and treat conditions ranging from heart disease to diabetes to depression. And the best part about nature therapy is that it is free!

We are fortunate to have plenty of opportunities locally to sit or walk in a park or forest and, better yet, visit the beach. The studies show that time spent near rivers, lakes or oceans have the biggest positive impact on health.

So get outside, enjoy some nature! As a result you will be happier, healthier and smarter.

Liza Horvath has over 30 years' experience in the estate planning and trust fields and is the president of Monterey Trust Management, a financial and trust management company. This is not intended to be legal or tax advice. Questions? Email liza@montereytrust.com or call 646-5262.